Conventionally, operation of plural audio signal processing devices such as digital mixers has been performed by connecting the devices using a network capable of transmitting plural audio signals and control signals in parallel.
In such audio signal processing devices, it is possible to connect an input port to handle an audio signal inputted from an input terminal, to a transmission port to handle transmission of the audio signal to the network, with a patch, and thereby immediately transmit the audio signal inputted from the input terminal to the network and subject the audio signal to signal processing with another audio signal processing device.
Further, it is possible to connect a reception port to handle reception of an audio signal from the network, to an output port to handle the audio signal outputted to an output terminal, with a patch, and thereby immediately output the audio signal received from the network, from the output terminal.
These connections are made when a part of a first audio signal processing device is used as a signal input/output device to provide a terminal for signal input from a network or signal output to the network. For example, the connections enable signal processing in which an audio signal inputted from an input terminal of the first audio signal processing device is subjected to signal processing with a second audio signal processing device, and then the processed signal is outputted from an output terminal of the first audio signal processing device.
Further, in addition to the above technique, there is an also known technique to store (save) the settings of signal processing at respective time points in a digital mixer (operation parameters to be described later) at once, as one scene, in a scene memory, then recall (call) a desired scene from the stored plural scenes in accordance with necessity, and reflect the scene in signal processing. Further, a recall safe technique to, upon this recall, designate a parameter of a part of the scene, and prevent recall with respect to the parameter, i.e., to maintain a parameter value before the recall, is known.
The recall safe is described in e.g. PTL1.